SUMMARY.
Temperature induces variation in the rate of growth. In accurate determination of the growth, the disturbing effect of radiation of heat has not been eliminated.
A continuous record of growth under uniform rise of temperature gives the Thermo-crescent curve, from which the rate of growth at any temperature may be deduced.
Different plant-tissues exhibit characteristic differences in their cardinal points of growth. In Kysoor, growth is arrested at the temperature minimum of 22°C. The optimum temperature is at 34°C., after which growth-rate declines and becomes completely arrested at 58°C. At 60°C. there is a sudden spasmodic contraction of death.
In other plants the cardinal points are different. In some plants the optimum growth is attained at 28°C. and remains constant up to 38°C.
XII.—THE EFFECT OF CHEMICAL AGENTS ON GROWTH
By
Sir J. C. Bose,